System of motor control.



PATENTED SEPT, 10, 1907.

W. H. POWELL.

SYSTEM OF MOTOR CONTROL.

APPLICATION FILED APR.16,1906.

INVENTOR WilliamHPowell ATTORNEY WITNESSES Ja w...

1m: NORRIS PETFRS cov, WASHINGTON, u, c.

UNITED STATES PATENT OFFICE.

WILLIAM H. POWELL, OF NORWOOD, OHIO, ASSIGNOR TO ALLIS-CI'IALMERSCOMPANY, A

CORPORATION OF NEW JERSEY, AND THE BULLOCK ELECTRIC ll'l'ANUFAOTURING COM- PANY, A. CORPORATION OF OHIO.

SYSTEM OF MOTOR CONTROL.

Specification of Letters Patent.

Patented Sept. 10, 1907.

Application filed April 16, 1906. Serial No. 311,828.

To all whom. it may concern:

Be it known that I, WILLIAM H. POWELL, a citizen of the United States, residing at Nor-wood, in the county of Ilamilton and State of Ohio, have invented certain new and useful Improvements in Systems of Motor Control, of which the following is a full, clear, and exact specification.

My invention relates to motor control systems and especially to control systems for motors requiring great variations in speed in a minimum time.

The object of my invention is to enable the speed of a motor to be rapidly varied, with minimum loss of energy. I'Ieretofore it has been proposed to have the motor armature supplied by a special generator armature, the motor field being constant and the generator field varied in accordance with the speed desired. This necessil ates a motor and a generator oi a very much larger capacity than required by the load, for the n1aximum voltage and maximum current supplied by the genenitor to the. motor are not used simultaneously, but rather the maximum voltage is used with a comparativcly small current, and the maximum current with a comparatively small voltage.

With my invention, the generator and the motor are not required to be of much, it any, greater capacity than required by the load, for the maximum current and maximum voltage are used simultaneously or near] y so. That is when the current is a maximum, the voltage is at least near the maximum, and vice versa.

Another sometimes disadvantageous feature of the prior arrangement before referred to is that the field of the motor at least, and usually the field of the generator must be separately excited. IVith my arrangement both of these fields as well as the motor armature are excited by the generator.

In one aspect my invention comprises the method of controlling the speed of an electric motor, which consisis in supplying the motor with current from a generator, and inversely varying the field strength of the motor and the electromotive force of the generator in alternate steps.

In a more specific aspect my invention comprises the method of regulating the speed of an electric motor, crmsisting in mechanically generating electrical energy, supplying this energy to the motor armature and to the field coils of both generator and motor, and inversely varying in alternate steps the current strengths in the lield coils of the generator and the motor.

In another aspect my invention consists of the com- 50 hination of a generator, a motor supplied thereby and means .l'or inversely varying the field strengths of the motor and generator in alternate steps.

More specifically considered my invention consists of the combination of a dynamo-electric generator, a moance varying arm ol which is shown at 8.

tor whose field and armature windings are both supplied 5 5 by said generator, and means for inversely varying the electromotive force of said generator and the field strength of said motor alternately step by step.

In a still more specific aspect, my invention consists of a motor control system comprising a self-excited generator, a motor whose field and armatures are both supplied thereby, and a rh eostat so connected and arranged that during part of-its movement it controls resistance in the motor armature circuit, and during the remainder of its movement, it controls resistance in the field circuits of both the generator and the motor.

Other features of my invention will appear in the following description and accompanying drawings, and will be more particularly pointed out in the appended claims.

Figure l is a diagram showing my invention with separate starting and regulating rheostats. Fig. 2 is a similar diagram showing all the rheostats under the control of a single handle.

The generator 1 is driven by any suitable means, and supplies the mains 2 and 3. Between these mains are connected in multiple to each other the generator field winding 4, the motor armature 5, and the motor field Winding 6. In each of these three circuits is included a variable resistance. The motor may be used to drive any desired load.

In Fig. l the motor armature circuit includes the variable resistance or starting rheostat 7, the resist- In the generator and motor field circuits are the variable resistances 9 and 10 respectively, controlled by the single rheostat arm 11.

The contact ring 12 is connected to the main 3.

The resistances 9 and 10 are so arranged that as the arm 11 is moved the resistances are inversely varied in alternate steps, the movement of arm 11 from one contact button to the next in the same series serving to vary the motor speed in two distinct steps, first by shunting a section of each resistance, thereby removing from its circuit that one of said sections which was previously in circuit, and second by opening said shunts, thereby inserting the other of said resistances into its circuit. By varying the relation of the Width of the controller arm at the contacts, the width of the contacts themselves, and the space between adjacent contacts, the extent of movement of the controller arm may be made the same for each step, or the same for alternate steps while different for successive steps.

The alternate variation of the resistances of the two field circuits makes the speed changes of the working motor twice as gradual as simultaneous variation would.

When the arm 8 is in its extreme left hand position, as shown in dotted lines, the motor armature circuit is broken. At this titne the arm .11 preferably in its extreme right hattd position as also shown in dotted lines. so that tlte wltole resistance 9 is in the generator tield circuit. and none of the resistance 10 is in tlte motor lield circttit. Thus the generator tield is at its weakest and the motor held at its strong t. As the arm 8 is moved ttavards the right tlte tnotor armature circuit is completed and the resistance 7 then gradually cut ottt. Alter the arm 8 has reached its extreme right hand or full line position. it is preferably not again moved ttntil the motor is to be stopped. lor the resistance 7 is for starting purposes only. To crease tlte speed of the armature 5. the arm 11 now moved to the left. thus gradually and in alternate steps cutting ottt resistance 5) and ctttting itt resistance It). %y the strengthening oi the generator tield dtte to the diminished resistance of the tield circuit. the the generator is increased This increases the electromotive l'orce impressed on tlte motor armature 5. and the current. through said artnat ure. resulting in an increased speed 01' the motor. The weakening or the motor lield due to the increased resistance of its lield circuit causes a still l'urther increase ol' speed of the Inotor.

The resistances oi the parts ti and 10 are so proportioned that the movement of arm 11. to the let't decreases the current through the winding ti, although the dil't'ercnccof potential between the mains 2 and 3 is increased. In other words the ratio of resistance increase of the motor lield circuit is greater than the electromotive force of ratio of voltage increase oi the generator. A movement oi the arm 11 towards the right causes strengthcuit. and the remainder ol' it iii the other, the relation between the parts being determined by the position oi the arm 11, which is connected to the main 3 and controls all the resistances When the arm 11 is in its extreme right hand position as shown in dotted lines, the motor armature circuit is broken, the motor licld is at its strongest and the generator held at its weakest, for the whole (11' resistance 13 is in the generator tield circuit. .\s the arm 11 is moved to the left. the motor armature circuit is completcd and the starting resistance T is gradually cttt out. After the starting rcsistance T has been cttt out. further moyement ol' the arm 1-1 to the left caust... a strengthening of the generator licld attd a weakening of the tnotor lield in alternate steps, more or lcss ol the resistance 13 being transl'errcd irom the generator licld circuit to the motor field circuit and being temporarily short-circuitcd during the transfer. Thus a movement of arm 11 to the left causes an increa e in the motor speed, and a movement to the right causes a. corresponding decrease.

If desired, the arm 11 may be movable far enough to the right to break the lield circuits of the generator and the motor, but, as shown, the contacts should be so arranged that these lield circttits are broken after the motor armature circuit, and, when the arm is moved in the opposite direction, made before the tnotor arm-.e tttre circuit.

It is obviotts that when the starting res' controlled by the same handle as the licld rcststancc, it is not; necessary to have resistance for the two ticld circuits combined, for in the rhcostat arrangements oi Fig. 2, the two resistances fl and 11) ot' Fig. 1 might be subs ttted for the single resistance 21. the othcr parts remaining the same.

By the term inversely I do ttot wish to limit myself to exact inverse prt'tportion. but intend that the term should include any increase in one and dccrcase in the other of the two parts spccilit d.

I have described my invention in what. I now ccnsidcr to be its preferred l'orm, but many details ol' connection and arrangement can b vari d without departing from the spirit: of the invention. All such obviotts modilications I consider to come within the scope of my invention.

ancc is What I claim as new, and desire to sccure by l.cttcrs Patent is:-

l. The method o1 regulating the speed of an clectric motor which consists in inversely varyi g itt alternate lcps its ticld strength and the clectroanotive t'orce impressed upon its armature.

L. The method or controlling the speed of an electric mo tor. which consists in supplying the motor with currcnt, from a generator. and inverscly varying in alternate stcps the tield strength of the motor and the elcctroanotiv t'orco ot' the generator.

3!. The method of regulating the speed ot. an electric motor. consisting in mechanically generating cloctrtcal cn- '3' supplying the energy to the motor. and invcrscly varying the ticld str ngths ot. the motor and th generator in alternate steps.

r. The method of operating an electric motor at varying speed. which consists in converting mechanical energy ittto electrical energy. supplying the electrical energy to the motor. and inversely varying alternately step by step the olectt'oanotive t'orce ot' the electrical energy and the lltltl strength of the motor.

5. The method of varying the current through thc armature of an electric motor. which consists in supplying the armature ot' the motor with current from a source of ya riahle electroanotive t'orce. and inversely varying in altcrnatc steps the clcctro-tnotivc force of said sourcc and thc tield strength of the motor.

i. The method of controlling the speed of an electric motor. consisting in supplying the tield and armatttrc ot' the motor from a source ol' variable clcctromotivc force, and inversely varying in alternate steps the clcctro-motivc t'orce at said source and the lield strength of tltc motor.

T. The method of varying the speed ot an electric inc-tor. consisting in converting mcchanical energy into electrical energy. supplying the electrical energy to both the, held and armaturc oi the motor. and lnverscly varying in altcrnatc steps the electroanotive force of said electrical energy and the held strength of the tnotor.

The method of regulating the spced o1 an clectt'ic mo tor ccnsisting in mechanically generating electrical ctr crg supplying this energy to the motor armature and to the ticld coils of both generator and tnotor. and inversely vary in alternate stops the current strengths in the ticld coils ot the generator and the motor.

.1. The method of regulating the speed of an clcctric tor. consisting in mechanically generating electrical ctr crgy. supplying this energy to the generator ticld coil and to the motor armature and held coil. and varying in altcr nate steps the tield strengths of the generator and tho lllotol.

lit. The method of inct'casit the speed o1. an clcctric motor. which consists itt supply ng the motor with current from a generator. attd increasing the elcctl'o-lltotivc t'orco ot' the generator and weakening the tield ot. the motor in alternate steps.

lllttvarying in alternate steps the field strength of the motor and the electro-motive torce ol' the source of electricity.

ll. A motor control system comprising a dynamo-electric generator, :1 motor supplied thereby, and means for invels ly val 111g in alternate steps the electromotive force oi the ge1'1erator and the field strength of the motor.

if). A motor control system comprising a source of V3: riable electromotivc force, a motor armature supplied thereby. a hold winding tor the armature, and means for rscly val ng in alternate steps the clectromotive force of said source and the strength 01. current in said field winding.

lti. A motor control system comprising a source of variable clcctromotive force, a, motor armature and field winding supplied thereby, and means for inversely varying in alternate steps the electromotlve force of said source and the field strength of said motor.

l7. A motor control system comprising a dynamo-elem tric genera tor, a motor whose field and armature windings are both supplied by said generator, and means for i11- vcrselyvarying in alternate steps the clectromotive force ot said generator and the field strength of said motor.

lH. A motor control tom comprising a self'excited dynanurelectlic generator, :1 motor whose held and armature windin s are both supplied thereby, and means tor invers y varying in alternate steps the current strengths in the field windings of the generator and the motor.

in. A 111otor control s stem comprising a self-excited dynamo-clectiric generator, a motor whose field and armature windin: are both supplied thereby, and means for varying the hold strengths of the generator and the motor in alternate. steps.

:20. A motor control'systeni, comprising a source of electricity. a motor supplied thereby, and means for in creasing the electromotivc force of the source and weakening the field oi the motor in alternate steps 21. A motor control system com 1rising a dynamo-electric generator. a motor supplied thereby, and means for decreasing the clectromotive force of the generator and increasing the hold strength of the motor in alternate steps.

22. A motor control system, comprising a generator, a motor supplied thereby, variable resistances in the ficld circuits ol. the generator and the motor, and means for inversely varying said resistances in alternate steps.

35;. A motor control system, comprising a generator, a motor supplied thereby, variable resistances in the field circuits of the generator and the motor, and a single arm for inversely varying said resistances in alternate steps.

Li. A motor control system, comprising a generator, a motor supplied thereby, a starting resistance in the motor armature circuit. resistances in the field circuits of the generator and the motor, and means for inversely varying said field resistances in alternate steps motor supplied thereby. a starting resistance in the motor armature circuit. resistances in the field circuits of the generator and the motor, and a single arm for inversely varying said field resistances in alternate steps.

26, A motor control system. comprising a generator, a motor supplied thereby. a starting resistance in the motor armature circuit. resistances in the field circuits of the generator and the motor, and a single arm for inversely said field re stances in alternate steps and for cutting out said starting res tancc.

27. A motor control system, comprising a self-excited generator, a. motor whose field and armature circuits are both supplied thereby, variable resistances in the field cir- A motor control system, ctnnprising a generator, a

cuits of the generator and the motor, and means for inversely varying said resistances in alternate steps.

28. A motor control system, comprising a se xciting gcnerz'ttor, a. motor whose field and armature circuits are both supplied thereby, variable resistances in the lield circuits of the generator and the motor, and a single arm for inversely varying said resistances in alternate steps.

20. A motor control system, comprising a sell Xcited generator, 21 motor whose field and armature circuits are both supplied thereby, a. starting resistance in the motor armature circuit, resistances in the field circuits of the generator and the motor. and means for inversely varying said field resistances in alternate steps.

:90. A motor control system comprising a self-excited generator, a motor whose field and armature circuits are both supplied thereby, a starting resistance in the motor armature circuit, resistances in the field circuits of the generator and the motor, and a single arm for varying said field resistances inversely.

31. A motor control system comprising a self-excited generator, a motor whose field and arma ire circuits are both supplied thereby. a starting resistance in the motor armature circuit, resistances in the field circuits oi the generator and the motor, and a single arm for varying said field resistances inversely and for cutting out: said starting resistance.

3.2. A motor control system comprising a generator. a motor supplied thereby, variable resistance in the field circuits of the generator and motor. and av sin le rhcostat arm arranged to decrease the resistance in one field circuit and increase it in the other in alternate steps 33. A motor control system comprising a selfiexcited generator, a. motor whose field coil and armature are sup plied thereby, variable resistance in the field circuits of the generator and the motor, and a single rhco. t arm arranged to decrease the resistance in one field circuit and increase it in the other in alternate steps.

34. A motor control system, comprising a source of electrici y a motor supplied thereby, a starting resistance in the motor armature circuit, and a unitary means for cutting out said starting resistance, increasing the electromotive force of the source, and weakening the field of the motor.

A motor control system, comprising a source of electricity, a motor supplied thereby, a starting resistance in the motor armature circuit, and a single arm for first cutting out said starting resistance and then increasing the elcctromotive force of said source.

36. A motor control system comprising a self-excited generator, a motor whose field coil and armature are both supplied thereby, and a rheostat so connected and arranged that during part of its movement it controls resistance in the motor armature circuit, and during the remainder of its movement it controls resistance in the field circuits of both the generator and the motor.

37. A motor control system, comprising a generator, a motor supplied thereby, and a rheostat so connected and arranged that during one part of its movement it controls resistance in the motor armature circuit and during another part of its movement it controls resistance in the generator field circuit.

38. A motor control system comprising a self-excited generator, a motor whose field coil and armature are both supplied thereby, and a rheostat so connected and arranged that during part of its movement it controls re sistance in the motor armature circuit and during the remainder of its movement it controls resistance in the generator field circuit.

39. A motor control system comprising a generator, a motor supplied thereby, and a rheostat so connected and arranged that during one part of its movement it controls resistance in the motor armature circuit, and during another part 01' its movement it controls resistance in the field circuits of both the generator and the motor.

40. A motor starting system, comprising a generator, a motor supplied thereby, and a. starting rheostat connected and arranged to first remove resistance from the motor armature circuit and then remove resistance from the generator field circuit.

41. A motor starting system comprising a generator, at

motor supplied thereby. and a starting rheostat connected and arranged to lirst remove resistance t'rom the tnotor armature circuit and then in alternate steps remove rty sistance from the generator tield circttit and insert resistance in the tnotor tield circuit.

42. A motor control s stem comprising a sell'cxcited generator. a motor whose held coil and armature are hoth supplied therehy, and a st rting rheostat connected and d to ttrst remove re lance from the motor at t ture cltcuit and then remove re tance from the generator t'teld circuit.

42;, A motor control system comprising a selt'c'tcited enerator. :1 motor whose tield coil and armature are hoth supplied therehy, and a starting rheostat connected and arranged to til-st remove resistance from the motor tnre circuit and then in alternate steps remove ance from the generator tield circuit and insert ance in the motor tield circuit.

4- In COIlllliLttlt'iOll. a generator. a motor. leads from the generator armature to one of wltich one terminal of the motor armature. the motor tieltl winding, and the generator tield winding are each connected. and a riteostat to one point of which the other generator lead is connected and to other points of which the other terminals of tlte tttotor armature. the motor field winding and the generator iield winding respectively are connected.

4?). In comhination. a generator, a motor. leads from the generator armature, and a rheostat directly connected to one the generator leads. and between which and the other lead. the motor armature. the motor tleld winding, and the generator tleld winding are connected.

it}. In comhination. a generator. a motor. leads from the generator arutature. and a the tat. directly connected to one o1 the generator leads, and hetwecn which and the other lead. the motor armature. the motor tield windin and the generator ttcld winding are connected in multiple.

47. In comhtnalton. a generator. a motor. leads from the generator armature, and a rheostat directly connected to one of the generator leads. and hetween which and 1] other lead. the motor armature. the motor tield windin and the generator ticld winding are connected. whcrclty the latter are all under the control of the rhcostat.

4.5. In comhination. a generator. at tnotor. leads from the generator armature, and a rheostat directly connected to one of the generator leads, and hetwcen which and the other lead. the motor armaturev thc motor tield winding and the generator tield winding are connected itt multiple. whereby the current strengths through the latter are all varied hy the rheostat so that movement ot the rhcostztt arm in one direction increases the motor speed and in the other direction decreases said speed.

In t intony whereot l ailix my signature, in the presence of two witnessesv 

